Concrete structures such as pipelines and manholes that are buried beneath the surface are difficult and costly to replace and, therefore, are repaired or rehabilitated when leaks develop in such structures. For example, repairing sewer pipes which have developed leaks has proven to be an expensive operation, normally involving disruption of sewer services. One of the most common solutions has been to dig up the section of leaking sewer pipe and then replace it with new pipe which is suitably attached to the existing sewer pipe. However, the expense of this method is readily apparent, especially in urban setting, as is the disruption of sewer service. The same holds true for the replacement of other non-subterranean structures that are formed from concrete that serve to enclose a fluid handling device such as a pump, pipeline, tank and the like.
Concrete structures are particularly susceptible to corrosion and erosion due to contact with or use in transporting liquids that are acidic in nature or that include some amount of solid component, respectively. Over time, the concrete structure subjected to such use will corrode and/or erode, causing wall portions of the structure to be eaten away and ultimately causing the structure to leak. As leaking liquid escapes from a subterranean pipe the ground surrounding the pipe serving as a foundation is eroded away from contact with the pipe, thereby leaving the already structurally weakened pipe without foundational support which may result in catastrophic structural failure.
Devices and methods for in-place surfacing or rehabilitation of concrete structures, to avoid the costly alternative of removal and replacement of such structures, have been developed and are known in the art. For example, U.S. Pat. No. 2,794,758 discloses a method and apparatus for in-place lining of a pipeline to protect the pipeline from the effects of corrosion and erosion. The apparatus comprises a housing that encloses a reel of flexible liner therein. The housing is attached at an outlet end to one end portion of the pipe to be repaired. A liquid pressure source, such as water and the like, is connected to an inlet end of the housing. Liquid entering the housing from the liquid pressure source imposes a pressure against a backside portion of the liner that has been attached at one end to a surface portion of the pipe. Continued exertion of liquid pressure against the liner backside surface causes the liner to unwind from the reel and be displaced through the length of the pipe. As the liner is displaced through the pipe the liquid pressure imposed against the backside surface causes the liner to unfold and be pressed against the wall surface of the pipe. Accordingly, this apparatus and method for repairing a pipeline relies on liquid pressure to dispense and place a flexible liner against the pipe wall portion requiring repair. This apparatus is, however, practically limited to the repair of pipelines only and, more particularly, to pipelines having a relatively small diameter, e.g., on the order of from 5-20 inches in diameter.
U.S. Pat. No. 3,132,062 discloses a method of in-place lining of conduit. The method comprises using a version of the housing and reel apparatus disclosed in U.S. Pat. No. 2,794,758, discussed above, that has been modified to include adhesive rollers disposed adjacent the housing end portion attached to the pipe. The method is an improvement of the method recited in U.S. Pat. No. 2,794,758, involving applying an adhesive material to the backside surface of the folded liner as the liner is being dispensed within the pipe to promote adhesion of the liner with an adjacent pipe wall surface. Again, however, this apparatus and method is limited only to the repair of pipelines and, more particularly, to pipelines having a relatively small diameter, e.g., on the order of from 5-20 inches in diameter.
U.S. Pat. No. 4,170,248 discloses a method for repairing sewer pipes by inserting a thin, flexible liner within the sewer pipe. The liner has an outside diameter that is less than the inside diameter of the sewer pipe, thereby forming an annular space therebetween. A top portion of the sewer pipe is removed at one location to expose the liner disposed therein. Packing is inserted at each sewer pipe end portion to seal off the annular opening between the liner and sewer pipe walls. The annular space between the sealed off ends is filled with a low viscosity cement by pouring the cement into a hole surrounding the removed top portion of the sewer pipe such that the cement can freely enter and fill the annular space. The cement is poured to a level above the top of the sewer pipe to provide a hydrostatic head to effect migration of the cement through the annular space between the liner and pipe and to the sealed ends. A overflow tube drilled into the top portion of the sewer pipe near each sealed end portion to provide an indication of whether the annular space is filled. This method, however, is also limited to repairing only pipelines and, more particularly, pipelines that are positioned in a horizontal orientation.
U.S. Pat. No. 4,792,493 discloses a corrosion resistant coating and liner combination used for repairing a water system pipe or reservoir comprising spray applying a polyurethane coating to a surface to be repaired and then adhering a sheet of polyvinyl chloride to the surface of the polyurethane coating. The polyvinyl chloride sheet is prepared for bonding to the surface of the polyurethane by applying a polyurethane primer-activator to the surface of the sheet. The polyvinyl chloride sheet is chemically bonded to the polyurethane coating by reaction of the primer activator and the polyurethane coating to provide a chemically resistant pipe liner. This method, however, does not provide long term leak protection as further cracking of the pipe is transmitted to an adjacent polyvinyl chloride sheet via the polyurethane coating, which causes the sheet to also crack and, thereby, permitting the escape of liquid from the pipe.
U.S. Pat. No. 5,101,863 discloses a method of rehabilitating underground pipes with an expanding helical wound liner. The method involves forming a helical wound liner made from a synthetic resin by winding a continuous strip of the resin around a virtual cylinder, of smaller outside diameter than the inside diameter of a pipe to be repaired, and interconnecting adjacent side edges of the strip together with a removable wire rod. The liner is then inserted into the pipe to be repaired and the leading end of the liner is attached to the inside wall of the pipe. The wire rod is removed, causing the liner to expand against the inside diameter of the pipe. As the wire rod is removed from the liner a device inserted between the outside diameter of the liner and the inside diameter of the pipe deposits a foam back filling material onto the outside surface of the liner. The device deposits the back fill material as it is retracted from the pipe so that such back fill material is applied simultaneously to that section of the liner that is expanded against the pipe wall. This method is also limited to use in repairing only pipelines and, more particularly, is practically limited to repairing pipelines having a relatively moderate diameter in the range of from 12-36 inches in diameter.
U.S. Pat. No. 5,102,263 discloses a method of renovating and/or protecting sewers and pipes comprising forming a liner from lengths of PVC panels, placing the panels around the wall of the pipe, and butt-joining together end portions of panel. The panels are configured having complementary edge configurations so that each panel portion that is butt-joined together may be clipped together along edge portions with an adjacent panel portion. The backside surface of each panel includes T-shaped formations that extend outwardly away from the backside surface to contact an adjacent wall surface of the pipe. If needed, due to corrosion that has eaten away a section of the sewer wall, holes can be drilled in the sewer wall (post installation of the liner) and grout pumped into the cavity between the liner and sewer wall to provide support to the liner. This method is limited in that it applies only the renovation of sewer pipes and, more particularly, to the repair of an entire diameter section of the pipe, due to the interlocking nature of the panels and the lack of attachment means for supporting an individual panel against the sewer wall.
U.S. Pat. No. 5,190,705 discloses a method for lining large-diameter pipes comprising the steps of supporting a tubular lining within the pipe by using supporting props, injecting a hardenable mass into a space between the liner and the inside pipe wall surface, allowing the hardenable mass to cure, removing the props, and repeating the cycle for the next tubular lining section. The tubular liner may include T-shaped formations that extend outwardly away from a backside surface to anchor it solidly to the hardenable mass. This method is limited in that applies only to the repair of pipelines and relies on the use of props to temporarily support the tubular liner in position against the pipe wall surface while the hardenable mass is injected and cured, thereby increasing repair difficulty and the time associate with completing such repair.
It is, therefore, desired that a device be constructed and method be devised to use the device to facilitate the surfacing or rehabilitation of a wide range of concrete structures, including pipes, that serve to contain and/or transport a volume of liquid. It is desired that the device and method be able to accommodate the surfacing or rehabilitation of structures having different geometries and sizes. It is desired that the device and method facilitate quick surfacing or repairs of such structures without having to use forms, props or other specialized equipment to install and/or retain the surfacing or rehabilitating device into place. It is also desired that the surfacing or rehabilitating device be capable of protecting against leakage from the structure in the event of future structure damage.